mx records google apps

I am setting my domain up with google apps, and i added the mx records like i normally would with my other hosting companys and the emails work great, a few days has passed and it is still saying 'checking MX records'. So a few hours ago i changed them to excatly the same way as you have in you demo with the TXT file at the bottom which i have not used before. Is this needed with WP for it to work? Can you tell me more please.